Two-stroke internal-combustion engine



R. BEACON TWO-STROKE INTERNAL COMBUSTION ENGINE Filed March 30. 1923 Patented Get. 7, 1924.

UNITED STATES PATENT OFFICE.

' TWO-STROKE INTERNAL-COMBUSTION ENGINE.

Application filed March 30, 1923.

To all whom it may concern:

Be it known that I, RONALD DEACON, a subject of the King of Great Britain and Ireland, and a resident of Harlesden, county of M iddlesex, England, have invented a certain new and useful Improvement in Two- Stroke lnternal-Combustion Engines, of which the following is a specification.

The present invention has for its object the provision of an improved two-stroke internal combustion engine adapted for motor vehicles, cycles, navigation, and for motive purposes.

Usually the induction and preliminary compression of the gaseous mixture takes place in the crank case, and said mixture is transferred to the working cylinder at the end of the explosion stroke, while the previously exploded charge is being exhausted to atmosphere.

Broadly, and according to the present invention, there is induced, from the atmos phere, and compressed, a charge of air only into an enclosed air and gas-tight crank case, and such charge is transferred to the working cylinder, for scavenging purposes, during the exhaust internal towards the end of the explosion stroke, and during the compression stroke there is introduced into the working cylinder, from an annular chamber formed by a continuation of the working cylinder and the engine piston and a trunk ring hereinafter referred to, a rich gaseous mixture which was drawn into said annular chamber during the explosion stroke, means being provided to check and control the flow of fuel mixture and the air required for scavenging, and also for effecting the reversibility of the engine.

In order that the said invention may be the more readily understood, reference is to be had to the following description and accompanying drawing, which is a view, partly in section and partly in elevation, of a two-stroke internal combustion engine constructed in accordance with the invention.

In carrying out the invention, the engine consists of a main or working cylinder 1 mounted on or formed in one with a cylinder 2, whose bore is of greater diameter than the bore of the working cylinder 1, and a combustion cylinder 3 detachably mounted on the working cylinder 1, the whole, as

Serial No. 628,816.

one, being mounted on an enclosed air and gas-tight crank case 4.

In the cylinder 1 there is adapted to reciprocate a trunk piston 5, the same, which extends into the cylinder 2, being operably connected with the crank shaft 6 by crank 7 and connecting rod 8.

Slidably mounted on and between the trunk piston and the inner wall of the cylinder 2 is an annular trunk ring or compression piston 9, the same dividing the space in cylinder 2 into two chambers 10 and 11 respectively, the chamber 10 communicating with the crank case a, while the chamber 11 is, at its upper end, provided with an inverted U-shaped passage 12, controlled by a non-return ball valve 13, said passage 12 further communicating with a carburetor, not shown on the drawing. The chamber 11, is the charging chamber, also at its upper part communicates with the combustion chamber 3 by way of passage 14, 14, said passage at its upper end being controlled by a mushroom valve 15, and at its lower end by a non-return ball valve 16.

The lower chamber 10, which chamber 10 is the compression chamber, communicates by passage 17 and non-return ball valve 18, with the atmosphere and also with the combustion chamber 3 by way of non-return ball valve 19, passage 26 and mushroom valve 29.

Ports 22 communicate with the exhausts 23, which exhausts 23 communicate with the atmosphere by way of a silencer, not shown on the drawing. The combustion chamber 3 is provided with valve caps 20, and spark plug 21, and to ensure perfect fit and working of the piston 5 the same is provided with piston rings 24, said piston 5 also working in scraper rings 25 provided in grooves in the lower part of the working cylinder 1, and to ensure perfect fit and working of the trunk ring 9 against said piston 5 and the inner wall of the cylinder 2, said trunk ring 9 has its inner and shorter skirt provided with scraper rings 27 and its outer and longer skirt with piston rings 28, said trunk ring 9 being actuated in advance of the crank from the crank axle 6 by means of an eccentric 30 and eccentric rod 31 arranged on each side of the crank 7.

Further, each eccentric, which is loose,

the air in the chamber 10. and crank case 4: is compressed by the downward move ment of the annular trunk ring 9 and the piston 5.

As the piston 5 uncovers the ports 22,

the exploded gases escape into exhaust passages 23, and, simultaneously, scavenge;

ing air under compression, from the lower part of chamber 10 and crank case 4 1s forced int-othe combustion chamber-'3 by, way of passage 17 valve 19, passage 26 and.

mushroom valve 29, scavenging said combustion chamber 3 and theworkingcylmder 1, and providing some of the air required forthe next succeeding charge of fuel mixture. Simultaneously, and prlor to its lnduction lnto the combustionchamber, scavenging air is compressed in the chamber 10, and

also inthe crank case" 4. On the instroke of the piston 5, the exhaust is completed and the ports 22 closed, and at thesametime a rich chargeof gaseous mixture is: forcibly inducted, by the upwardimovement of the trunk ring'9, by way of passages:

14, 14 and valves 16 and 15, into the combustion chamber 3 where it is still further compressed, with the air already therein, ready for ignition on completion of the instroke. Simultaneously, a supplyof fresh air is drawn, from atmosphere, by way of valve 18 and passage 17, into thelower chamber 10" and crank case 41; the repetition of these operations resulting in the engine being driven on a two-stroke principle, or oneimpulsestroke per revolution.

I claim:

A two-stroke internal combustion engine comprising in combination, an air-tight crank-case, a crank-shaft in; said. crankcase, superimposedcylinders supported on said crank-case, the lower cylinder having.

a larger bore than the upper cylinder, a

pistonv slidable within the upper, cylinder and having portion extending downward 1y into the lower: cylinder, means for reciprocating said pistonfrom said cranks shaft, atrunk ring, slidable on the; piston and on the wall of the lower cylinder to divide said cylinders into charging and compression chambers respectively which vary ,in' volume as the trunk ring reciprocates, means for reciprocating saidtrunk ring in advance of the piston,'a suction valve controlled passage connectingthe. compression chamber with the atmosphere, and

valve-controlled passages connecting the chambers. e 1

In testimony whereof I have affixed my. signaturehereto this 13th day; of. March' v a RONALD nEnooN'. 

